The purpose of using molecular graphics, computer modeling, and sequence analysis is to gain insight into macromolecular or biological structures. Using molecular graphics, models can be computationally constructed which may be useful in deciding between two or more alternative interpretations of biochemical or structural data. Computer modeling is often important to attempt to understand biophysics or other biochemical relationships, and how these relate to biological structures. Sequence analysis uses the none-dimensional amino acid sequence of proteins together with both Fourier analysis and other predictive algorithms to attempt to identify parts of the sequence which may have a regular structure. These inter-related computational methods are used to extrapolate known structural information for the purpose of predicting useful three- dimensional relationships. Often, three-dimensional structural information is unavailable or experimentally intractable. Three studies currently in progress include collaborations with LSBR, NIAMS to predict the structure of macromolecules; with PSL, DCRT to study computer models of biopolymers; and with BEIP, NCRR to create new software for the analysis of gel electrophoresis. Progress this year has involved continuation of a long-term study of the structure and assembly of intermediate filaments, which has resulted in a new publication. A new study involving computer models of biopolymers has yielded new information on mechanisms for diffusion, and has been submitted for publication. Work on understanding the physics of gel electrophoresis has resulted in another publication.